Interspecific tree named ‘Crimson Heart’

ABSTRACT

A new and distinct variety of interspecific tree. The following features of the tree and its fruit are characterized with the tree budded on ‘Nemaguard’ Rootstock (non-patented), grown on Handford sandy loam soil with Storie Index rating 95, in USDA Hardiness Zone 9, near Modesto, Calif., with standard commercial fruit growing practices, such as pruning, thinning, spraying, irrigation and fertilization. Its novelty consist of the following unique combination of features that are desirable in a new variety: 
     1. Heavy and regular production of large, red flesh, clingstone fruit. 
     2. Fruit with very good flavor and eating quality. 
     3. Fruit with firm flesh, good storage and shipping quality. 
     4. Fruit with a good balance between sugar and acid having high soluble solids of 15.5° Brix.

BACKGROUND OF THE VARIETY

In the field of plant genetics, we conduct an extensive and continuingplant-breeding program including the organization and asexualreproduction of orchard trees, and of which plums, peaches, nectarines,apricots, cherries and interspecifics are exemplary. It was against thisbackground of our activities that the present variety of interspecifictree was originated and asexually reproduced by us in our experimentalorchard located near Modesto, Stanislaus County, Calif.

PRIOR VARIETIES

Among the existing varieties of plums and interspecific trees which areknown to us, and mentioned herein, ‘Laroda’ Plum (non-patented), ‘QueenAnn’ Plum (non-patented), ‘Friar’ Plum (non-patented), interspecifictrees ‘Plum Parfait’ (U.S. Plant Pat. No. 4,338), and ‘Flavorosa’ (U.S.Plant Pat. No. 10,285).

ORIGIN OF THE VARIETY

The present new and distinct interspecific tree [(Prunussalicina×(Prunus salicina×(Prunus salicina×Prunus armeniaca)×(Prunussalicina×Prunus armeniaca))×(Prunus salicina×Prunus armeniaca)] wasoriginated by us in our experimental orchard as a first generation crossbetween the seedling 59EF110 and ‘Plum Parfait’ Plumcot (U.S. Plant Pat.No. 4,338). The seedling (59EF110) originated from a cross between twoseedlings, one seedling originated from a cross of ‘Laroda’ Plum(non-patented) with ‘Queen Ann’ Plum (non-patented). The second seedlingoriginated from crossing two seedlings, the first cross made with aseedling selected from an open pollinated ‘Friar’ Plum (non-patented)with a plumcot and, from this cross a seedling was selected and backcrossed to the same plumcot. The plumcot originated from an openpollinated ‘Red Beaut’ Plum (U.S. Plant Pat. No. 2,539) seed. We plantedand maintained a large group of these first generation crosses, growingon their own root, under close observation, during which time thepresent new seedling exhibited distinct and desirable fruitcharacteristics and was selected in 1995 for asexual propagation andcommercialization.

ASEXUAL REPRODUCTION OF THE VARIETY

Asexual reproduction of the distinct variety of interspecific tree wasby budding to ‘Nemaguard’ Rootstock (non-patented), a standard rootstockfor interspecific trees in California, as performed by us in ourexperimental orchard near Modesto, Calif., and shows that reproductionsrun true to the original tree and all characteristics of the tree andits fruit are established and transmitted through succeeding asexualpropagations.

SUMMARY OF THE VARIETY

The present distinct variety of interspecific tree[(Plum×(Plum×Plumcot)×(Plumcot))×(Plumcot)] is of large size, vigorous,upright in growth and a productive and regular bearer of large, firm,clingstone fruit with very good flavor and eating quality. The fruit isfurther characterized by having an attractive red flesh, holding firm onthe tree 10 days after maturity, having good storage and shippingquality and having high soluble solids of 15.5° Brix with a good balancebetween sugar and acid. In comparison to the Plumcot ‘Plum Parfait’(U.S. Plant Pat. No. 4,338), the present variety has larger leaves, hasplum like fruit with no pubescence, which is larger in size andapproximately one week earlier in maturity. In comparison to theinterspecific tree ‘Flavorosa’ (U.S. Plant Pat. No. 10,285) the newvariety has a higher winter chilling requirement, blooming 1 week laterin the spring, the fruit is more round in shape and is 7 to 10 dayslater in maturity.

PHOTOGRAPH OF THE VARIETY

The accompanying color photographic illustration shows typical specimensof the foliage and fruit of the present new interspecific variety. Theillustration shows the upper and lower surface of the leaves, anexterior and sectional view of a fruit divided in its suture plane toshow flesh color, pit cavity and the stone remaining in place. Thephotographic illustration was taken shortly after being picked (shippingripe) and the colors are as true as is reasonably possible in a colorrepresentation of this type.

DESCRIPTION OF THE VARIETY

The following is a detailed botanical description of the present varietyof interspecific tree, its flowers, foliage and fruit, as based onobservations of 5 year old specimens budded on ‘Nemaguard’ Rootstock(non-patented) and grown near Modesto, Calif., with color terminology(except those in common terms) in accordance with Reinhold Color Atlasby A. Kornerup and J. H. Wanscher.

Tree:

Size.—Large. Pruned 10 to 12 feet in height and width, primarily foreconomical harvesting of fruit.

Vigor.—Vigorous. Tree growth of 5 to 6 feet in height and 4 to 5 feet inwidth the first growing season. Varies with type of soil and culturalpractices.

Growth.—Upright growth habit. Heavy production tends to spread tree atbearing age.

Branching habit.—New growth upright. Crotch angle 25 to 30 degrees,spreading increases with weight of fruit.

Productivity.—Productive. Usually sets 2 or more times desired fruit formarketable crop load. Thinning and spacing of fruit necessary.

Bearer.—Has set full crop load 4 consecutive years. No alternate bearingobserved.

Density.—Medium dense. Center branches removed to open tree to vaseshape for improved sun light throughout the tree, which enhances growthof fruitwood and brix of fruit.

Hardiness.—Hardy for all stone fruit growing areas of California, grownin USDA Hardiness Zone 9.

Trunk:

Size.—Large. Circumference — 21 inches, measured 9 inches above groundon a 5 year old tree. Varies with soil type, climatic conditions andcultural practices.

Stocky.—Medium. Varies slightly with type and fertility of soil.

Surface texture.—Medium rough. Roughness increases with age of tree.

Color.—Varies from grayish brown to brown (7-D-2) to (7-E-4).

Branches:

Size.—Medium. Circumference — 8 inches, measured 48 inches above groundon a 5 year old tree.

Surface texture.—Varies from smooth on new growth to medium rough.Roughness increases with age.

Lenticels.—Numerous, average 65 in 4 square inch surface. Average length{fraction (3/32)} inch, increases in size as branch grows larger.Average width {fraction (3/64)} inch. Color varies from grayish yellowto banana yellow (4-B-5) to (4-B-7).

Color.—One year old growth varies from olive green to light golden brown(2-F-6) to (6-B-6). Older growth varies from oak brown to bronze brown(5-D-6) to (5-E-5).

Leaves:

Size.—Large. Average length 4¼ inches. Average width 1¾ inches.

Form.—Oblanceolate.

Apex.—Acuminate.

Base.—Cuneate.

Margin.—Doubly serrate.

Thickness.—Medium.

Surface texture.—Upper surface varies from smooth to lightly indentedover veins, glabrous. Lower surface relatively smooth except for smallridges of midrib and pinnate venation, glabrous.

Petiole.—Average length ½ inch. Average width {fraction (3/32)} inch.Color — light olive green (29-D-6). Grooved longitudinally.

Glands.—Size — small. Average diameter {fraction (1/32)} inch. Globose.Number — varies from 1 to 4, average number 3. Located on base of leafblade and upper portion of petiole. Color — grayish yellow (3-B-7).

Color.—Upper Surface varies from deep green to dark green (29-F-7) to(29-F-8). Lower Surface varies from dull green to bracken green (29-D-6)to (29-E-7).

Midvein.—Pronounced, extends into petiole. Color — light olive green(29-D-6). Pinnate venation.

Flower buds:

Size.—Small. Average length — {fraction (9/32)} inch. Average diameter —{fraction (3/16)} inch. Four days before opening.

Hardiness.—Hardy in all stone fruit growing areas of California, grownin USDA Hardiness Zone 9.

Pubescence.—Wanting.

Form.—Plump, free, conical.

Shape.—Obtuse, becomes more elongated as bud matures.

Color.—White (29-A-1).

Peduncle.—Average length — {fraction (13/32)} inch. Average width —{fraction (3/64)} inch. Color — light green (29-B-7).

Number of flower buds per spur.—Average 17. Varies from 10 to 25.

Flowers:

Size.—Medium, non-showy. Average height — {fraction (15/32)} inch.Average width — {fraction (47/64)} inch.

Color.—White (29-A-1).

Pistil.—Normally one, varies from 1 to 2. Average length — {fraction(5/16)} inch, stigma {fraction (1/16)} inch below anthers. Color — whiteto yellowish white (1-A-1) to (1-A-2). Pubescence — wanting.

Stamens.—Number varies from 38 to 49 per flower. Average number — 43.Average filament length — {fraction (19/64)} inch. Filament color —white to pale yellowish white (1-A-1) to (1-A-2). Anther color — lightyellow to vivid yellow (3-A-6) to (3-A-8).

Petal.—Number — five, alternately positioned to sepals. Shape —elliptic, narrows at point of attachment. Size — medium. Average length— {fraction (25/64)} inch. Average width — {fraction (11/32)} inch.Color — white (29-A-1). Surface — smooth, edges of petals curvedslightly toward center to form bowl shape around anthers and pistil.Margin varies from smooth to slightly scalloped.

Sepals.—Five. Triangular, apex slightly rounded. Alternately spacedbetween petals. Average length — {fraction (9/64)} inch. Average width —{fraction (5/64)} inch at point of attachment. Color — upper surface —grayish green in center to pistachio green near outer edges (28-C-5) to(28-C-4), glabrous. Lower surface — light green to grayish green to,glabrous. Varies with age of maturity.

Pollen.—Abundant, pollen sacs full. Color — light yellow to yellow(3-A-5) to (3-A-7).

Pollenizer.—Self-sterile, pollenizer required. Some of the factorsaffecting blooming dates that must be considered when selecting apollenizer for specific areas. Winter chilling hours, number of heatunits to excite bud initiation, type of rootstock, soil type, culturalpractices and climatic conditions.

Fragrance.—Slight.

Blooming period.—Date of First Bloom Feb. 19, 2000. Date of Petal FallFeb. 28, 2000. Varies slightly with climatic conditions.

Number of flowers per bud.—Average number 3. Varies from 1 to 4.

Peduncle.—Average length — {fraction (15/32)} inch. Average width —{fraction (3/64)} inch. Color — light green (29-B-7).

Fruit:

Maturity when described.—Firm ripe.

Date of first picking.—May 28, 2000.

Date of last picking.—Jun. 2, 2000. Varies slightly with climaticconditions.

Form.—Globose, nearly rounded, slightly retuse at apex and base on mostfruit.

Size.—Large. Average diameter axially — 2¼ to 2⅜ inches. Averagetransversely in suture plane 2¼ to 2⅜ inches. Average weight 127.8grams. Average weight varies with number fruit per tree, fertility ofsoil and climatic conditions.

Suture.—Very shallow, extends from base to apex.

Ventral surface.—Nearly smooth, very slightly lipped.

Apex.—Varies from nearly rounded to slightly retuse.

Base.—Varies from flat to slightly retuse.

Cavity.—Rounded to slightly elongated in suture plane. Average depth — ⅜inch. Average breadth — ½ inch.

Stem:

Size.—Medium. Average length — ½ inch. Average width — {fraction (1/16)}inch.

Color.—Linden green to olive yellow (2-C-5) to (2-D-8).

Flesh:

Ripens.—Nearly uniform, only slightly earlier near apex.

Texture.—Firm, meaty.

Fibers.—Few, small, tender.

Firmness.—Good, comparable to ‘Flavorosa’.

Aroma.—Slight.

Amydgalin.—Undetected.

Eating quality.—Very good.

Flavor.—Very good, sweet, good balance between acid and sugar.

Juice.—Moderate, enhances flavor.

Brix.—15.5° soluble solids. Varies with amount of fruit per tree,climatic and soil conditions.

Color.—Cerise to ruby red (12-C-8) to (12-D-8), some slight pale yellowbleeding into flesh around pit cavity. Pit cavity color — dark ruby(12-E-8).

Skin:

Color.—Light yellow to yellow (4-A-5) to (4-A-7) ground color.Overspread with violet brown to brownish violet (10-F-8) to (11-E-8).Very small, randomly spaced areas of ground color showing at skinsurface giving speckling pattern.

Thickness.—Medium, minimal scarring or discoloring during picking andpacking trials.

Surface texture.—Smooth.

Bloom.—Moderate, complete coverage.

Tendency to crack.—None.

Tenacity.—Tenacious to flesh.

Astringency.—None.

Stone:

Type.—Clingstone.

Size.—Large. Average length 1 inch. Average width ¾ inch. Averagethickness ⅜ inch.

Form.—Obovoid.

Base.—Usually flat, varies from flat to rounded.

Apex.—Cuspidate. Average length — {fraction (3/32)} inch.

Surface.—Lightly pitted throughout. Several small ridges extending frombase approximately ½ distance toward apex. One long groove on each sideof suture extending from base to apex.

Sides.—Varies from equal to unequal with one side extending further fromsuture plane.

Tendency to split.—None.

Color.—Varies from tan to light brown (5-B-4) to (5-B-6) when dry.

Use: Dessert. Market — local and long distance.

Storage quality: Good, held 3 weeks in cold storage at 38° to 42° F.without internal breakdown of flesh or appreciable loss of flavor oreating quality.

Shipping quality: Good, picking, packing and transporting of fruit gaveminimal bruising of flesh or skin scarring during shipping trials.

Disease resistance/susceptibility: No specific testing for relativeplant/fruit disease resistance/susceptibility has been designed. Underclose observation during planting, growing, and harvesting of fruit,under normal cultural and growing conditions near Modesto, Calif., noparticular plant/fruit disease resistance or susceptibility has beenobserved. Any variety or selection observed during indexing of plantcharacteristics, with abnormal fungus, bacterial, virus or insectsusceptibiity is destroyed and eliminated from our breeding program.

The present new variety of interspecific tree, its flowers, foliage andfruit herein described may vary in slight detail due to climate, soilconditions and cultural practices under which the variety may be grown.The present description is that of the variety grown under theecological conditions prevailing near Modesto, Calif.

We claim:
 1. A new and distinct interspecific tree, substantially as illustrated and described, characterized by its large size, vigorous, upright growth and being a productive and regular bearer of large, clingstone, red flesh fruit with very good flavor and eating quality; and, in comparison to the interspecific tree ‘Flavorosa’ (U.S. Plant Pat. No. 10,285), the new tree blooms one week later in the spring, produces fruit that is more round in shape and is 7 to 10 days later in maturity. 